Shell body and method of making same



Jan. 2, 1945. D. M. WEIGEI. 2,366,663

SHELL BODY AND METHOD OF MAKING SAME Filed Nov. 26, 1942 Y INVENIoR. DAN/E1. M WE/GEL .ATTO/PNEKS Patented Jan. 2, 1945 2,366,663 SHELL Boor AND METHOD or Mimmo. SAME Daniel M. Weigel, Detroit, Mich., assignor to The Standard Products Company, Detroit, Mich., a corporation of Ohio Application November 26, 1942, Serial No. 466,990

(ci. 21a-1.21)

1 Claim.

The invention relates to novel and improved body structures for hollow explosive projectiles of light or heavy caliber, and further relates to novel and improved methods of forming, and assembling such shell body structures.

The methods of manufacturing hollow shell bodies, as heretofore practiced while varying somewhat in detail by reason of the projectile size, design, and source of supply, universally involve the development of the shell body from solid stock. Project-iles about three inches in diameter or smaller are machined from solid rod or bar stock, and in the sizes larger than three inches in diameter they are formed from billets by forging, upsetting, or extrusion, followed by a plurality of machining, boring, cutting aud/or grinding operations. All such procedures result in a substantial scrap loss in the form of turnings and borings. This is particularly undesirable by reason of the present metal shortage, especially in the high grade steels required for projectile two chambers, said method including certain metal cutting and metal deforming steps to be described hereinbelow for securing said partition v drawing in which stock. .The multiplicity of fabricating and machining operations, both internally and externally of the shell body also entails a considerable loss of time, and in many cases the use of bulky and costly upsetting or extrusion presses or forging hammers.

` or percussion charge fails to work.

One object of the present invention is the provision of a novel and improved shell body struc- .ture for hollow projectiles.

A A further object is the provision of a shell bodyA of such design and contour that it lends itself readily to simplified cutting, boring, and metal forming methods.

.A further object of the invention is the provision of a shell body which can be fabricated by a simplified machining procedure and with greatly reduced scrap metal losses.

A further object of the invention is'the provision of a method of manufacturing a shell body from a seamless steel tubular blank of predetermined length, by a series of steps to be described hereinbelow.

A further object is the provision of a method of manufacturing from seamless steel tubing a shell body of the type wherein an internalr transversely disposed partition divides the shell into Fig. 1 is a longitudinal section of a seamless steel tubular blank for a shell body;

Fig. 2 is a cross-sectional view taken on the line 2-2 of Fig. 1;

Fig. 3 is a section similar to Fig. 1 but showing the blank after suitable machining operations;

Fig. 4 is a sectional view of an end plug or base plug for the rear end of the shell body;

Fig. 5 is a longitudinal view of the shell body showing the end plug and nose piece or fuse in position at respectively the rear and front ends of the shell, the nose piece or fuse being shown in elevation;

' Fig. 6. is a longitudinal sectional view of a partially machined seamless tubular'` steel blank suitable for a double chambered shell body;

Fig. y' is a central longitudinal sectional view, brokenaway at the left and right ends of the drawing, showing a further stage in the preparation of the internal cylindrical periphery of the shell body;

Fig.- 8 is a transverse sectional view taken on the line 8-8 of Fig. 7;

Fig. 9 is an enlarged sectional view of the stepped portion of Fig. 8;

Fig. 10 is a view similar to Fig. '7 but showing a spacing disk inposition, and also showing thev operating head of an upsetter ram or plunger preliminary to heading in the spacing disk;

Fig. 11 is a view similar to Fig. 10 but showing the position of the several elements at the termination of the power stroke of the upsetter ram;

Fig. 12 is a longitudinal sectional View of the ,nished shell rbody showing'the end plug, the

spacing disk,'and thev nos'e piece in their respectively iinal' positions, thenose piece or fuse being shown in elevation.

Before the present invention is described in detail, it is to be understood that such invention is not limited to the details of construction or the specic arrangement of parts herein illustrated or described, as the invention obviously may take other forms.'y It also is to be understood that the phraseology or terminology herein employed is for the purpose of description and not of limitation. Figs. 1 to 5 inclusive illustrate successive steps in the development of a single chambered explosive projectile or tracer bullet from a blankv 20 consisting of a length of seamless tubing shown for instance 20 mm. in diameter. The outside di ameter and wall thickness of blank 2l may be suitably selected to ultimately conform to the required specifications, bearing in mind vthe simple machining operations to bev described. 'I'he inside diameter of the blank .requires no additional machining operations with the exception of the portion extending inwardly a small distance from each end. i

As shown in Fig. 3 one end of the blank is given a coniform,'slight1y convex taper, at 2|. The inner periphery of the tapered end is threaded at 22 to receive a fuse plug or nose piece 23 (Fig. 5) The inner periphery of the other end of the blank is machined to a stepped arrangement providing one or more internal annular shoulders 24. An end plug 25 is machined to a steppedcontour complementary to that of the tube so as to seat in the stepped portion of the tube. When thus seated by means of a pressed fit, the terminal edge 26 of the tube blank may be spun, rolled, or otherwise turned at; 28 into an inset annular groove 2l around the rear edge of the plug as best seen in Fig. 5. The circumferential periphery of the blank may be provided with one or more annular grooves or' depressions 29 for carrying a riding band not shown of relatively soft metal. n

While the method just disclosed for the retention `of the end plug is simple and eiiicient, other effective methods will occur to those skilled in the art on consideration of 4the various requirements of the general construction of which Figs. 1 to 5 are exemplary.

The outside diameter of the blank shown in Figs. 1 to 5 may be machined o'r ground to final dimensions in familiar fashion. One ofthe striking advantages of the manner of fabrication of a shell body as here shown is the simplicity of the procedure, the elimination of a number of diverse forming and shaping steps, and the considerable saving of metal which formerly was lost as turnings, borings, etc.

Figs. 6 to 12 inclusiveillustrate successive steps in the development of a dual chambered shell body from a tubular blank, such as that shown in Figs. 1 and 2, to a finished shell as shown in Fig.

12. A shell of the type shown in Fig. 12 is gen-` erally of heavier caliber than-the type described in connection with Figs. 1 to 5.

In the manufacture of a dual chambered shell body such as will now be described, a seamless steel tubing is cut to a blank 20 of the proper diameter, length, and wall thickness such as shown in Fig. 1. The blank is provided with a slightly convexed coniform taper 2|- at its outer front end, and with an internally threaded porl tion 22 on its inner front end. It may likewise be provided with riiiing band grooves 29, and may be machined or ground to accurate external 'contour as already described with respect to the prior,

single chambered embodiment,

A multiple step reamer (not shown) is inserted .from one end, here shown as the frontend, to reduce the wall thickness in two successive steps.

and form three coaxial, adjacent bore portions of increasing diameter, 35, 36 and 31, this machining operation coming to a stop intermediate the ends vof the blank so as to leave two internal annular shoulders I8 and 3l, transversely disposed with respect to the tube bore, as shown in Fig. 7, and in enlarged section in Fig. 9. K

A spacer or disk 4II of a thickness somewhat less than the longitudinal extent of the intermediate bore 36 and of a diameter sufllcientto be seated by/ a press iit in peripheral contact with bore Il and having a circumferential portion of one face in contact with shoulder ,is inserted to the position shown in Fig. 10.. A plunger or ram 4l having a driving head Portion in slidlnly tted relationship to bore 31 is advanced from the open end of bore 31 into abutting contact with shoulder 39 of intermediate bore (Fig. 10). Further advance of the ram (Fig. 11'), under pressure developed hydraulically or otherwise as is familiar to those skilled-in the manner of operation of power presses, causes the shoulder metal I9 of bore 36 to be -inturned (Figs. l1 and l2) to provide a permanently positioned inwardly extending A retaining flange 42 which locks disk 4l in place as a bulkhead to divide the bore of the blank into two spaced chambers 4lr and 44, chamber 43 being of greater diametrical extent than chamber 44. The manner of retention and support to the blank in suitable dies during this ilange upsetting operation needs no illustration since familiar to those skilled in the art of vfabrication and mechanical deformation of metals.

As compared with the present standard method of machining shell bodies of this character from forged billets, or laboriously effecting gradual development of the.contour by successive piercing and upsetting operations, the simplicity of the Y present operation and its economic advantages` are immediately apparent.

A suitable end plug or disk 4l of any desired character is afiixed in the shell base, and a nose piece or fuse 41 is attached at the front end. In

this dual chambered embodiment the percussionV charge or tracer charge is placed in the chamber 44 before iinally aiilxing the disk or plugv 48 in place. The thickness and general characteristics of the disk 46 are determined by the requirements as to size and type of shell, and its intended purt e I have described the several 'simple machining operations in a specific sequence, it is of course obvious that the order of some of the operations may be varied or transposed, and that two or more of said operations may be carried on simultaneously so as to further facilitate the operation, and increase the rate of production.

What I claim is: A method of making a body for an explosive shell comprising cutting a blank of predetermined length and dimensions from seamless steel tubing, increasing the internal bore diameter of said blank throughout a portion of its length to lform three coaxial. adjacent, stepped .bore portions and two transversely extending annular shoulders, disposing a spacing disk transversely within said blank in peripheral contact with the intermediate w tial portion of the other disk face ,whereby the shell body is provided with two chambers separated by said disk, one of said chambers being of greater cross sectional diameter than the other.

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